# -*- coding: utf-8 -*-
"""
Created on Wed Aug 28 12:57:43 2024

@author: lsh
"""

import copy
import numpy as np
from datetime import datetime


# 字符串列表化
def string_to_ls(str):
    return [i.split(' ') for i in str.split(',')]


# 获取位置
def get_loacl(arr, target):
    # r, c = np.where(arr == target)
    # return r, c
    for i in arr:
        for j in i:
            if j == target:
                return arr.index(i), i.index(j)


# 获取可以和0交换位置的元素
def get_elements(arr):
    r, c = get_loacl(arr, '0')
    elements = []
    if r > 0:
        elements.append(arr[r - 1][c])  # 上面的元素
    if r < 2:
        elements.append(arr[r + 1][c])  # 下边的元素
    if c > 0:
        elements.append(arr[r][c - 1])  # 左面的元素
    if c < 2:
        elements.append(arr[r][c + 1])  # 右面的元素
    return elements


def get_child(arr, e):
    # 深拷贝与浅拷贝！!
    arr_new = copy.deepcopy(arr)
    r, c = get_loacl(arr_new, '0')
    r1, c1 = get_loacl(arr_new, e)
    arr_new[r][c], arr_new[r1][c1] = arr_new[r1][c1], arr_new[r][c]
    return arr_new


def is_goal(arr, goal):
    return arr == goal


class state:
    def __init__(self, state, parent):
        # state是一个3x3的ls矩阵
        self.state = state
        self.parent = parent

    def chidren(self):
        chidren = []
        for i in get_elements(self.state):
            child = state(state=get_child(self.state, i), parent=self)
            chidren.append(child)
        return chidren


# 打印求解路径
def print_path(n):
    if n.parent == None:
        return
    else:
        print('↑')
        print(np.array(n.parent.state))
        print_path(n.parent)


if __name__ == '__main__':
    initial = '0 1 3,4 2 5,7 8 6'
    goal = '4 1 3,7 0 5,8 2 6'
    # initial = '0 7 8,2 5 4,3 6 1'
    # goal = '7 5 8,2 4 1,3 6 0'
    # initial = '4 0 1,6 8 5,7 3 2'
    # goal = '5 8 2,1 0 4,6 3 7'
    initial_arr = state(string_to_ls(initial), parent=None)
    goal_arr = string_to_ls(goal)
    start = datetime.now()
    open = [initial_arr]
    close = []
    while len(open) > 0:
        open_tb = [i.state for i in open]
        close_tb = [i.state for i in close]
        n = open.pop(0)
        close.append(n)
        if is_goal(n.state, goal_arr):
            print(np.array(n.state))
            print_path(n)
            print('最优求解过程如上')
            break
        else:
            for i in n.chidren():
                if i.state not in open_tb:
                    if i.state not in close_tb:
                        open.append(i)
    end = datetime.now()
    print('--' * 20)
    print('--' * 20)
    print('--' * 20)
    print('搜索路径如下：')
    for i in close[:-1]:
        print(np.array(i.state))
        print('↓')
    print(np.array(close[-1].state))
    print('共耗时:', end - start)
    print('搜索步骤为{}'.format(len(close) - 1))